1. Field of the Invention
The present invention relates generally to tissue treatment during medical procedures. Specifically, the present techniques provide automated and manual systems for treating tissue while using spectroscopic techniques to monitor a tissue parameter.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Numerous techniques are used to treat or remove tissue during invasive and non-invasive medical procedures. Such techniques include the heat sealing of tissues and vessels, the freezing of tissues by cryoablation, and the removal of tissue or fluids by suction. These techniques all require a high degree of skill in administering the treatments in order to maximum the therapeutic efficacy.
For example, sealing of vessels during surgical procedures used to be performed by the use of fine stitches. However, stitches have a number of problems, including: a tendency to leak; the need to leave a foreign object in the body; and the time it takes for the surgeon to place the stitches. A more modern technique for sealing vessels is to administer heat to the walls of the vessel while holding the walls together under pressure. The heat partially melts the collagen in the walls of the vessel, while the pressure forces the melted collagen together to form a plastic seal. Although this technique is faster than stitching, less likely to leak, and leaves no foreign objects in the body, the energy must be carefully controlled to avoid damaging the surrounding tissues.
The heat may be generated in the tissue by the use of a radio frequency electrical current, which causes the tissues between two electrodes to heat and melt. The procedure may be controlled by monitoring the change in the impedance of the tissue between the electrodes, and lowering the energy administered as the changing impedance indicates that the sealing of the tissue is nearing completion. However, depending on various factors, including the conductivity of the surrounding tissues, a wider area may be exposed to the heat energy than is necessary for the treatment, potentially leading to undesirable damage.
Other techniques, such as cryoablation, may use thermocouples for monitoring the changes in the tissue during treatment. In cryoablation, a probe is connected to a refrigeration device and used to freeze tissues at the point of treatment. This freezing causes the formation of ice crystals in the cells, which ruptures the cell walls and causes the death of the frozen tissue. The practitioner may determine the area frozen by both the temperature and the appearance of the tissue. However, thermocouples may not accurately reflect the immediate temperature of the treated tissue either because of the time lag in the reading or the failure of probes to accurately determine extreme temperatures. As changes in the tissue may not be clearly visible, a larger area may be treated than is necessary for the therapeutic value obtained.
Still other techniques use a probe or needle connected to a suction device to remove tissue or fluids during medical procedures. An example of this technique may include, for example, liposuction, in which deposits of fat are removed from below the epidermis. Another common example involves draining fluids from the chest cavity, such as to relieve congestive heart failure or to remove fluid buildup from around the lungs after an injury. Suction techniques rely on the skill of the operator to ensure that the needle is located in the appropriate tissue type prior to activation of the suction device.